Brewen J G, Payne H S, Preston R J
Mutat Res. 1976 Apr;35(1):111-20. doi: 10.1016/0027-5107(76)90173-1.
Structural chromosome aberrations were analyzed in superovulated metaphase-I oocytes of the mouse, Mus musculus, at various times after a single acute dose of 200 R of X-rays. The aberrations seen were of the chromatid type, i.e., chromatid interchanges, isochromatid deletions and chromatid deletions. The aberration frequency was low during the interval 24 h to 5 days between irradiation and ovulation; peak frequency was reached when irradiation was given 14 days prior to ovulation. A dose-response study was made 14 days prior to ovulation at doses of 50, 100, 200, 300 and 400 R. A curve of these data indicated that a significant two-track component was present for both interchanges and deletions. Centromere staining revealed that symmetrical and asymmetrical interchanges occurred at approximately equal frequency and also that the asymmetrical equivalent of crossing-over was induced at a measurable frequency.
对小家鼠单次急性给予200伦琴X射线照射后不同时间超排卵中期I卵母细胞的染色体结构畸变进行了分析。观察到的畸变类型为染色单体型，即染色单体互换、等染色单体缺失和染色单体缺失。在照射与排卵间隔的24小时至5天期间，畸变频率较低；在排卵前14天给予照射时达到峰值频率。在排卵前14天，分别给予50、100、200、300和400伦琴的剂量进行剂量反应研究。这些数据的曲线表明，互换和缺失均存在显著的双径成分。着丝粒染色显示，对称和不对称互换的发生频率大致相等，并且以可测量的频率诱导出相当于交叉的不对称情况。
